This follow-up to my previous post seems like a logical progression on the subject of player immersion, as evidenced not only by the proliferation of music-related blogs, but of course, those seeking to add an extra 'something' to their sessions. In today's case, this 'something' comes by way of music, sound effects, or other audio-related elements one may add to the experience. With the availability and popularity of equipment designed to provide these effects, this option may be the most cost-effective method of immersion one can implement, as the impact of utilizing tools one may already have (mp3 player, home theater system, etc.) can be quite profound. As always, these tips are provided for Player and Host alike, as the enhancement of game quality should be an endeavor undertaken by all able participants.
When selecting a particular sound effect, it's important to maintain a level of compatibility with the overall pace of the session. For example, if a an action-packed, edge-of-your-seat, combat-heavy scenario is in mind, it would be prudent to select a similarly dynamic, fast-paced piece. Few things can calm a bloodthirsty spirit faster than a tranquil piece of classical music, or a meditative selection of the 'Chillout' genre. *cough*ImeanyouLhosreiff*cough*
Conversely, I advise you to avoid speed metal and anything of that sort during an upscale period of diplomacy (unless you feel like adding a touch of comedy to a particularly heated debate, of course).
Addendum: If done well (and sparingly), one can accomplish a rather Tarantino-esque flair by pairing a particularly gorey scene with aforementioned tranquil piece of classical music.
While considering pace appropriateness, please don't neglect to adequately pair the regular settings of your session with the theme of your song list. Case in point: one should generally avoid broadcasting a piece by 'Daft Punk' over the siege of a medieval stronghold (again, there are certain exceptions to this rule; such is the case of a dimension-/time-hopping campaign).
Lyrics in a song choice are often discouraged for their ability to draw attention from away from the action in front of them, or the narration a Host provides. The exception to this guideline would be a selection with a message thoroughly relevant to the situation at hand, though one is still forced to contend with speaking over the music.
As stated in the previous guideline, 'competing' with, or speaking over the music is discouraged, which is an issue that may arise when implementing an overly complex and engaging piece. An example of such is difficult to determine, but if the music you select tempts others to pause play and listen instead of acting with it, reconsideration may be necessary. An aural aid musn't take away from the experience, but it shouldn't add too much, either.
These are a bit more difficult to pull off, as they usually require the acquisition of a reliable soundboard, combined with the innate sense of timing necessary to successfully use them without breaking pace. If successful, however, this method can add an unforgettable depth to one's session, especially if running a horror/suspense scenario.
That's all for now, hope these help.